The story of titanium(construction-physics.com)
construction-physics.com
The story of titanium
https://www.construction-physics.com/p/the-story-of-titanium
187 comments
As a kid in my father's workshop we had several 4mm thick titanium plates, scavenged from some industrial stuff in USSR research facility nearby. I had a lot of fun getting my visiting friends tey to dent it with hammers. No matter how hard you struck it just didn't care. Only the oxidation patina would show some trace of impact. It was absolute magic to me. And so incredibly light!
When the USSR collapsed, a lot of defense companies pivoted to civilian production. A factory in my town was producing titanium shovel heads.
They were awesome, unbelievably light, but very durable. They also made nice sparks when dragged across concrete pavement.
They were awesome, unbelievably light, but very durable. They also made nice sparks when dragged across concrete pavement.
Decades ago, Sears sold magnesium stepladders. I've used one, and it's freakishly light, a 6-foot step ladder that you can walk around with balanced on one finger.
I've always wondered what a titanium one would be like.
I've always wondered what a titanium one would be like.
A lot heavier actually.
In an application like a stepladder, you have to work with certain minimum dimensions for the stepladder to be practical (eg rungs and sides have to fit in the hands nicely). You also have to have certain minimum thicknesses on the parts to have sufficient resistance to local deformation (eg dropping a hammer on the rungs). That forces the parts to be significantly larger and stronger than they otherwise would be. Which makes very lightweight metals like magnesium and aluminum the better choice, as you can make thick parts at the required dimensions at very little weight.
Climbing gear is a great example of this. Even though there's a segment of that market for which money is no object, the only use for titanium in climbing gear is certain specialized applications where corrosion resistance is important. Eg fixed gear mounted on sea-side cliffs. Because climbing gear has to have certain minimum dimensions to avoid damaging ropes, the very low density of aluminum wins over titanium's higher density/higher strength.
If you made a carabiner out of titanium it'd be stronger than necessary, and a lot heavier.
In an application like a stepladder, you have to work with certain minimum dimensions for the stepladder to be practical (eg rungs and sides have to fit in the hands nicely). You also have to have certain minimum thicknesses on the parts to have sufficient resistance to local deformation (eg dropping a hammer on the rungs). That forces the parts to be significantly larger and stronger than they otherwise would be. Which makes very lightweight metals like magnesium and aluminum the better choice, as you can make thick parts at the required dimensions at very little weight.
Climbing gear is a great example of this. Even though there's a segment of that market for which money is no object, the only use for titanium in climbing gear is certain specialized applications where corrosion resistance is important. Eg fixed gear mounted on sea-side cliffs. Because climbing gear has to have certain minimum dimensions to avoid damaging ropes, the very low density of aluminum wins over titanium's higher density/higher strength.
If you made a carabiner out of titanium it'd be stronger than necessary, and a lot heavier.
This is also why aircraft use aluminum, despite the major downsides (finite fatigue life, mainly). There’s just no way steel would work (far too heavy). Titanium is awesome but a royal pain to work with. Carbon fiber is starting to come in but it has issues to - although they’ll be overcome with time.
The Soviet Mikoyan-Gurevich MiG-25 was manufactured principally from stainless steel.
The result was a stunningly fast fighter aircraft, capable of Mach 3.2, though in practice engine overheating restricted operation maximum to Mach 2.83 (3,000 km/h), and even that for only 5 minutes at a time as the airframe and fuel would overheat. The MiG-25's mass necessitated huge wings (and overall dimensions), and limited maneuverability. Steel however provided better thermal-tolerance capabilities than aluminium, and lower cost and easier fabrication than titanium.
First flight 1964, introduced to active service in 1970.
That said, the aircraft is notable as an exception to your generally-applicable rule.
<https://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-25>
I suspect carbon fibre would also have thermal limitations for high-speed aircraft.
The result was a stunningly fast fighter aircraft, capable of Mach 3.2, though in practice engine overheating restricted operation maximum to Mach 2.83 (3,000 km/h), and even that for only 5 minutes at a time as the airframe and fuel would overheat. The MiG-25's mass necessitated huge wings (and overall dimensions), and limited maneuverability. Steel however provided better thermal-tolerance capabilities than aluminium, and lower cost and easier fabrication than titanium.
First flight 1964, introduced to active service in 1970.
That said, the aircraft is notable as an exception to your generally-applicable rule.
<https://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-25>
I suspect carbon fibre would also have thermal limitations for high-speed aircraft.
Steel structure won't be necessarily heavier cause density and strength are almost thrice as much as aluminium ? I think the issue with steel is that it for the required strength, the structure would be too thin that it would buckle under compression much sooner.
Titanium also doesn't have the resistance to abrasion that other metals have. There's stories of titanium bike frames being ruined because the rear tire was mounted incorrectly and ended up rubbing on the frame during a ride.
If you can 3D print titanium, then you can make a honeycomb structure overcoming this problem.
What is the response to stress by this build method? Will it fail gracefully over a lifetime of stresses? Any single big stress-event?
In terms of (rigid, diamond-frame) bicycles, this is why I’m still firmly in the steel camp. No aluminium, no carbon; just steel. It really does have an excellent combination of nice ride quality, low weight, high strength, good failure mode (I’ve broken a few frames, and they tend to just bend/sag, vs the rapid unscheduled disassembling of carbon/Al).
In terms of (rigid, diamond-frame) bicycles, this is why I’m still firmly in the steel camp. No aluminium, no carbon; just steel. It really does have an excellent combination of nice ride quality, low weight, high strength, good failure mode (I’ve broken a few frames, and they tend to just bend/sag, vs the rapid unscheduled disassembling of carbon/Al).
I can't comment on the plasticity of titanium.
But complex microstructures can be designed to have non-sudden failures. Eg. you could ensure that a visible crack appears at 0.75x the ultimate strength, yet doesn't fail till 1.0x the strength.
You can also design structures so that a 'crack' is either 1mm wide or not there at all (ie. no hairline cracks).
such features of microstructures are not free though - you will lose strength/weight to get them.
But complex microstructures can be designed to have non-sudden failures. Eg. you could ensure that a visible crack appears at 0.75x the ultimate strength, yet doesn't fail till 1.0x the strength.
You can also design structures so that a 'crack' is either 1mm wide or not there at all (ie. no hairline cracks).
such features of microstructures are not free though - you will lose strength/weight to get them.
> In terms of (rigid, diamond-frame) bicycles, this is why I’m still firmly in the steel camp. No aluminium, no carbon; just steel. It really does have an excellent combination of nice ride quality, low weight, high strength, good failure mode (I’ve broken a few frames, and they tend to just bend/sag, vs the rapid unscheduled disassembling of carbon/Al).
Bicycles don't have the minimum size problem GGP is talking about. Titanium is pretty much the perfect frame material (if you can afford it) - all the nice things you list (a bit stiffer than steel, but ride quality is still decent), but substantially lighter.
Bicycles don't have the minimum size problem GGP is talking about. Titanium is pretty much the perfect frame material (if you can afford it) - all the nice things you list (a bit stiffer than steel, but ride quality is still decent), but substantially lighter.
>Bicycles don't have the minimum size problem GGP is talking about.
They do, in a slightly different way. Bicycle frames are (broadly) stiffness-critical structures. Wider-diameter tubes have a higher specific stiffness because of the increased moment of inertia - that's why we use structures like tubes and I-beams instead of solid bars. Steel frames have skinny tubes, because they're limited by the minimum wall thickness of the tubing; increase the diameter too much and you have a tube that is very vulnerable to dents and very prone to buckling. Steel racing frames of the 1970s are remarkably flimsy, because framebuilders were pushing wall thickness to the absolute limit.
Aluminium bicycle frames are only lighter because the lower density allows you to retain an acceptable wall thickness on larger-diameter tubes. An aluminium frame with the same tube diameters as a steel frame would be considerably heavier than the steel frame, because an aluminium frame needs to be overbuilt to compensate for the lack of a defined fatigue limit.
All common steel alloys have essentially the same stiffness (~207GPa), but higher-strength steels allow us to use wider-diameter tubes with thinner wall sections; incidentally, this is why it's quite pointless to use an expensive tubeset in a lugged frame. CFRP obviously has immense specific stiffness, but it also allows frame designers to really optimise the geometry and use the material more efficiently.
Titanium is a really nice frame material, but it does have some significant issues in practical use. Titanium is very prone to embrittlement if there is any amount of contamination in the weld. Most framebuilders aren't capable of maintaining the level of cleanliness and the comprehensive gas purging required to produce really good welds in titanium, so it's very common to see titanium frames eventually crack around the welds.
To my mind the perfect material for a non-sporting frame was the superb Reynolds 953 maraging steel, but unfortunately it is no longer available. Reynolds 931 and KVA MS2 are still very good materials, particularly when fillet brazed rather than welded. CFRP obviously wins out in terms of pure performance, but I'm not sure that I'd ever trust an old and battle-scarred carbon frame on a hard descent.
They do, in a slightly different way. Bicycle frames are (broadly) stiffness-critical structures. Wider-diameter tubes have a higher specific stiffness because of the increased moment of inertia - that's why we use structures like tubes and I-beams instead of solid bars. Steel frames have skinny tubes, because they're limited by the minimum wall thickness of the tubing; increase the diameter too much and you have a tube that is very vulnerable to dents and very prone to buckling. Steel racing frames of the 1970s are remarkably flimsy, because framebuilders were pushing wall thickness to the absolute limit.
Aluminium bicycle frames are only lighter because the lower density allows you to retain an acceptable wall thickness on larger-diameter tubes. An aluminium frame with the same tube diameters as a steel frame would be considerably heavier than the steel frame, because an aluminium frame needs to be overbuilt to compensate for the lack of a defined fatigue limit.
All common steel alloys have essentially the same stiffness (~207GPa), but higher-strength steels allow us to use wider-diameter tubes with thinner wall sections; incidentally, this is why it's quite pointless to use an expensive tubeset in a lugged frame. CFRP obviously has immense specific stiffness, but it also allows frame designers to really optimise the geometry and use the material more efficiently.
Titanium is a really nice frame material, but it does have some significant issues in practical use. Titanium is very prone to embrittlement if there is any amount of contamination in the weld. Most framebuilders aren't capable of maintaining the level of cleanliness and the comprehensive gas purging required to produce really good welds in titanium, so it's very common to see titanium frames eventually crack around the welds.
To my mind the perfect material for a non-sporting frame was the superb Reynolds 953 maraging steel, but unfortunately it is no longer available. Reynolds 931 and KVA MS2 are still very good materials, particularly when fillet brazed rather than welded. CFRP obviously wins out in terms of pure performance, but I'm not sure that I'd ever trust an old and battle-scarred carbon frame on a hard descent.
> Bicycles don't have the minimum size problem GGP is talking about
Good point.
> Titanium is pretty much the perfect frame material[…]
Anecdotally - I understand it’s tougher to work with at about every single step. I’ve seen too many cracked Ti bikes/parts to sign up, I think. I understand the lust though.
Good point.
> Titanium is pretty much the perfect frame material[…]
Anecdotally - I understand it’s tougher to work with at about every single step. I’ve seen too many cracked Ti bikes/parts to sign up, I think. I understand the lust though.
Coincidentally, you can. https://www.sciencedirect.com/science/article/abs/pii/S00260...
NI think AI assisted development needs comments to make better informed decisions about the code Needed to accomplish the task.
Can you 3D print metals yet? That sounds quite difficult.
Prototyping - Metal 3D Printing - Dan Gelbart
https://youtu.be/nyYcomX7Lus?si=E-B5VkFeX9W0Twc4
https://youtu.be/nyYcomX7Lus?si=E-B5VkFeX9W0Twc4
Sort of! https://thevirtualfoundry.com
Not directly extruding it, but the end result is metal.
Not directly extruding it, but the end result is metal.
[deleted]
> Decades ago, Sears sold magnesium stepladders. I've used one, and it's freakishly light, a 6-foot step ladder that you can walk around with balanced on one finger.
As a slight aside, magnesium is also a very interesting material. It might be we're on the cusp of a major expansion in magnesium usage due to recent advancements
- Mining from seawater (about 1 kg Mg in 1000L of seawater), or existing brine tailings from other extraction activities. With cheap solar electricity this might drive the cost down considerably (below the extremely dirty production methods being used today in China), providing carbon-emission free production of essentially unlimited amounts.
- thixomolding, a die-casting / injection molding-like process where the material isn't completely melted (thixotropic state), producing parts with much less porosity than traditional die casting.
- New alloys that are less prone to fires and corrosion.
For slightly more details, see https://www.youtube.com/watch?v=OIv_Rfl0L_A
As a slight aside, magnesium is also a very interesting material. It might be we're on the cusp of a major expansion in magnesium usage due to recent advancements
- Mining from seawater (about 1 kg Mg in 1000L of seawater), or existing brine tailings from other extraction activities. With cheap solar electricity this might drive the cost down considerably (below the extremely dirty production methods being used today in China), providing carbon-emission free production of essentially unlimited amounts.
- thixomolding, a die-casting / injection molding-like process where the material isn't completely melted (thixotropic state), producing parts with much less porosity than traditional die casting.
- New alloys that are less prone to fires and corrosion.
For slightly more details, see https://www.youtube.com/watch?v=OIv_Rfl0L_A
Magnesium from mine tailings https://anrweb.vt.gov/PubDocs/DEC/GEO/TechReports/VGTR1998-1...
I had to do a double take on your "about 1 kg Mg in 1000L of seawater" stat, thinking it was for titanium, rather than magnesium.
For those curious, titanium is present in sea water, at 1 ppb! (magnesium is 1300 ppm)
For those curious, titanium is present in sea water, at 1 ppb! (magnesium is 1300 ppm)
Aluminum and magnesium are lighter than titanium at the same strength.
The idea is you can use less titanium in the application you would use aluminum, but this has limits. If your ladder was .200” wall thickness, you might in theory get away with a .070” titanium for the same weight, but you start running into mechanical stresses or assembly issues or manufacturing.
Titanium is useful when you need internal volume - most recently as an example by Apple. Aluminum was fine, but had thick walls. Steel allowed thinner was but was heavier. Titanium allowed for thin walls and more internal volume, but at a higher cost.
Basically, if you don’t have a size limit, aluminum is great! But most things have size limits, and titanium allows you to trade size for cost.
The idea is you can use less titanium in the application you would use aluminum, but this has limits. If your ladder was .200” wall thickness, you might in theory get away with a .070” titanium for the same weight, but you start running into mechanical stresses or assembly issues or manufacturing.
Titanium is useful when you need internal volume - most recently as an example by Apple. Aluminum was fine, but had thick walls. Steel allowed thinner was but was heavier. Titanium allowed for thin walls and more internal volume, but at a higher cost.
Basically, if you don’t have a size limit, aluminum is great! But most things have size limits, and titanium allows you to trade size for cost.
The iPhone 15 pro is mostly aluminum. There is about a 1mm thick band of titanium around an aluminum frame.
https://www.apple.com/newsroom/2023/09/apple-unveils-iphone-... https://www.youtube.com/watch?v=S_W73ouKtjU&t=605s
https://www.apple.com/newsroom/2023/09/apple-unveils-iphone-... https://www.youtube.com/watch?v=S_W73ouKtjU&t=605s
And that makes perfect sense.
Thick walls on the iPhone are what are going to prevent X Y area which I suspect they need more than thickness.
Thick walls on the iPhone are what are going to prevent X Y area which I suspect they need more than thickness.
Seems like marketing to me. They got rid of the stainless steel frame from previous models, switched back to aluminum, then added a pointless band of titanium so they could say Titanium in their marketing.
Magnesium stepladders are great until one catches on fire because you try to weld something onto it or get it too close to a welding torch. Then things get spicy.
Plus: doesn't magnesium oxidize more readily than other metals? I would worry that grandpa's magnesium ladder is a death trap.
Bulk metals are extremely difficult to ignite and magnesium in particular forms a very strong passivation layer on the surface as soon as it touches the air. Unless you're doing wildly inappropriate things like welding on it (tip: don't do this with any ladders, regardless of material), it's fine.
Huh. Now I want to buy a magnesium ladder and set it on fire.
If you do, take it out into the middle of nowhere first because you won't be able to put the fire out (unless you bring a Class D extinguisher--good luck finding one of those at your nearby hardware store). Don't put water on it because that just makes it burn hotter.
Damn, imagine having a titanium shovel! I want one!
https://nearzero.co/products/shovel
They exist! Meant for backpacking/back country work.
I spent a summer as a wilderness search and rescue intern/volunteer/grunt/mule during college and was shocked at how much weight could have been saved with better gear. There’s just a minimal market for it.
They exist! Meant for backpacking/back country work.
I spent a summer as a wilderness search and rescue intern/volunteer/grunt/mule during college and was shocked at how much weight could have been saved with better gear. There’s just a minimal market for it.
That company sells titanium pots, too. And they say “ Titanium leaves no metallic smell or taste.”
I don’t believe it. Titanium is, mechanically, a great material for a lightweight pot, but in my limited testing, I don’t think it’s inert enough. Green tea in a titanium pot is especially nasty.
I don’t believe it. Titanium is, mechanically, a great material for a lightweight pot, but in my limited testing, I don’t think it’s inert enough. Green tea in a titanium pot is especially nasty.
This is actually a plot point in H. Beam Piper's _Little Fuzzy_:
https://www.gutenberg.org/ebooks/18137
the audiobook read by Tabithat is just about professional quality and is highly recommended:
https://librivox.org/little-fuzzy-by-h-beam-piper/
https://www.gutenberg.org/ebooks/18137
the audiobook read by Tabithat is just about professional quality and is highly recommended:
https://librivox.org/little-fuzzy-by-h-beam-piper/
In the backpacking and bicycle-travel community, titanium pots are widely regarded as good only for boiling water in, since they don't distribute heat as well as aluminium for more complex cooking.
I’m well aware, but I don’t really believe this :). As far as I can tell, no very thin pot or pan distributes heat well [0], and no very thin pan cleans up well from cooked-on food when the cleaning supplies at hand while backpacking.
[0] Concretely, this means that, when cooking solid food, the parts of the pan where the food isn’t sinking heat adequately get too hot.
[0] Concretely, this means that, when cooking solid food, the parts of the pan where the food isn’t sinking heat adequately get too hot.
The non-stick aluminium pans from MSR, and perhaps other brands, do clean up well from food after cooking. In my experience (hundreds of nights of cooking while cycling the world), it is enough to wipe them clean with a dedicated towel or wet-wipe in order to pack them, and then they can be washed completely the next time one reaches a convenient water source.
I had similar experiences with titanium cookware. Could it be acting as a catalyst to something that would otherwise not happen?
I don’t know.
My current favorite cooking surface is the coating used on Hestan Nanobond. It’s sold as “titanium” but, from reading the patent, I think it’s a bunch of layers of CrN, TiN, and AlN, applied by PVD in a process optimized to produce an attractive gray color that looks a bit like metallic titanium. It seems very hard, very durable, and does not obviously react with any kind of food. (And even if it did, unless something oxidized the Cr to +6 and made it soluble, nothing that might leach out seems likely to be harmful.)
The patent seems to expire fairly soon, and maybe the process will take off. I wonder if this coating could be applied to a lightweight titanium pot with good results.
My current favorite cooking surface is the coating used on Hestan Nanobond. It’s sold as “titanium” but, from reading the patent, I think it’s a bunch of layers of CrN, TiN, and AlN, applied by PVD in a process optimized to produce an attractive gray color that looks a bit like metallic titanium. It seems very hard, very durable, and does not obviously react with any kind of food. (And even if it did, unless something oxidized the Cr to +6 and made it soluble, nothing that might leach out seems likely to be harmful.)
The patent seems to expire fairly soon, and maybe the process will take off. I wonder if this coating could be applied to a lightweight titanium pot with good results.
Oh, there's a market for lightweight backpacking gear, all right! Check out Backpacking Light for in-depth reviews.
Garage Grown Gear has some of the trendy light and ultralight stuff.
1. https://backpackinglight.com/
2. https://www.garagegrowngear.com/
Garage Grown Gear has some of the trendy light and ultralight stuff.
1. https://backpackinglight.com/
2. https://www.garagegrowngear.com/
Mountaineering ice screws. Its a dream for pro alpinists, since you have to drag every gram up there in thin air, so focus on weight saving is extreme, ie drilling holes into aluminum spoons before 8000m expeditions was normal in 70s-80s in eastern Europe block. Normal stainless steel ones are much heavier.
Those must have been soft hammers. Titanium isn't magic. It's neither as hard, nor as strong, as steel. It's a lot lighter, which makes it a wonder material in certain applications that can take advantage of it's excellent strength-to-weight ratio. But if max hardness, or strength at a given size, is what you are after, without a weight constraint, steel wins.
I mean, I'm no materials scientist but one google tells me that Titanium is AS strong as steel but much less dense. I just browsed through the top 10 Google results and everyone states that titanium is roughly equal to steel in strength but with various other benefits. So your comment is definitely off-base somewhere, you make it seem like steel is much stronger, which clearly isn't the case.
Read this for starters: https://www.thomasnet.com/articles/metals-metal-products/ste...
"When comparing the tensile yield strengths of titanium and steel, an interesting fact occurs; steel is by-and-large stronger than titanium."
Many people confuse this issue, because they're actually talking about measures of strength/weight ratios, on which titanium does really well. But if you are size limited rather than weight limited, steel is often a better material than titanium even when cost is no object.
"When comparing the tensile yield strengths of titanium and steel, an interesting fact occurs; steel is by-and-large stronger than titanium."
Many people confuse this issue, because they're actually talking about measures of strength/weight ratios, on which titanium does really well. But if you are size limited rather than weight limited, steel is often a better material than titanium even when cost is no object.
Every source says that titanium is as strong as the most commonly used steel. Sure if you're going for lesser used alloys of steel you may as well compare to lesser used alloys of titanium. Or just compare iron with titanium, as that's really comparing one element with another, and is the "fair" comparison.
And anyway, your original comment suggested someone was totally in the wrong for thinking a 4mm titanium plate was strong, which is obviously incorrect. 4mmm of titanium plate is clearly going to be really strong and resistant. They wouldn't make plane engines from it if it wasn't.
And anyway, your original comment suggested someone was totally in the wrong for thinking a 4mm titanium plate was strong, which is obviously incorrect. 4mmm of titanium plate is clearly going to be really strong and resistant. They wouldn't make plane engines from it if it wasn't.
> They wouldn't make plane engines from it if it wasn't.
...but they don't! Jet engines can only use titanium for certain low pressure, low temperature, sections. The high temperature parts are made from nickle/iron-based superalloys. And aluminum still gets significant usage, because for many geometries an aluminum part has a better strength/weight ratio.
Like I said, titanium is strong. But it's not magic. Stronger than any aluminum alloy, weaker than commonly used steel alloys. Hitting a 4mm plate of titanium with a hammer just isn't a very special experience. I've done it.
Hitting a 4mm tool steel plate definitely can be a special experience. Because it's so strong and hard that you could easily cause the thing to shatter, sending sharp shards in unpredictable directions...
...but they don't! Jet engines can only use titanium for certain low pressure, low temperature, sections. The high temperature parts are made from nickle/iron-based superalloys. And aluminum still gets significant usage, because for many geometries an aluminum part has a better strength/weight ratio.
Like I said, titanium is strong. But it's not magic. Stronger than any aluminum alloy, weaker than commonly used steel alloys. Hitting a 4mm plate of titanium with a hammer just isn't a very special experience. I've done it.
Hitting a 4mm tool steel plate definitely can be a special experience. Because it's so strong and hard that you could easily cause the thing to shatter, sending sharp shards in unpredictable directions...
No the parent is correct. Steel is by and large stronger than titanium of the same size. Pray tell what is this "most commonly used alloy of steel"? Because just fyi different steel alloys are used for different applications just like different titanium alloys are also used for different applications.
Titanium has excellent strength to weight properties compared to steel. A 4mm titanium plate would absolutely be dented by common shop hammers. This doesnt mean that "titanium isnt strong" it just means they have different material properties.
Titanium has excellent strength to weight properties compared to steel. A 4mm titanium plate would absolutely be dented by common shop hammers. This doesnt mean that "titanium isnt strong" it just means they have different material properties.
Steel has a range of strengths. The "most commonly used steel" is probably just mild steel and yeah Ti-6Al-4V is going to be the rough equal of mild steel on strength broadly assessed. But a high strength steel alloy will be three times that strong, and titanium can only be pushed so far.
I would use “cold roll” instead of “mild steel”.
But otherwise, yea irrc… Grade5 Ti (6AL4V) is approx equal to ultimate tensile of 303 stainless (extremely common) at 50% the weight.
BUT… Ti doesn’t even get close to 600 steels (like Inconel) or even common 17-4PH, etc.
But otherwise, yea irrc… Grade5 Ti (6AL4V) is approx equal to ultimate tensile of 303 stainless (extremely common) at 50% the weight.
BUT… Ti doesn’t even get close to 600 steels (like Inconel) or even common 17-4PH, etc.
Exactly.
Indeed, if your design goal is strictly "don't get dented when hit by a hammer", the "strongest" material could easily be a good synthetic rubber!
Indeed, if your design goal is strictly "don't get dented when hit by a hammer", the "strongest" material could easily be a good synthetic rubber!
For most non-architectural design goals striking the right balance of toughness strength and hardness is generally what you want correct? I would imagine for building a bridge you care much more about elasticity and creep strength.
Also fatigue resistance.
Bicycle design is a good example of where this matters: steel has a significant fatigue limit, and can endure cyclic stresses below that limit indefinitely. Aluminum has no fatigue limit, so any flexing is inevitably eating away at fatigue life. Thus aluminum bike frames have to be made much stronger and stiffer than otherwise necessary, to avoid bikes breaking unexpectedly due to fatigue. And that in turn means that aluminum bike frames don't have as much of a weight advantage over steel as you'd expect.
Bicycle design is a good example of where this matters: steel has a significant fatigue limit, and can endure cyclic stresses below that limit indefinitely. Aluminum has no fatigue limit, so any flexing is inevitably eating away at fatigue life. Thus aluminum bike frames have to be made much stronger and stiffer than otherwise necessary, to avoid bikes breaking unexpectedly due to fatigue. And that in turn means that aluminum bike frames don't have as much of a weight advantage over steel as you'd expect.
For a rigid road bike aluminum can definitely be made stronger and lighter, even though what you wrote about fatigue limit is technically true. People like steel because they feel it’s more comfortable to ride. For mountain bikes, you will find almost zero steel bikes. Here the stiffness and lightness of aluminum (and carbon fiber at the high end) is almost universally preferred.
One advantage that adds to the potential lightness of aluminum and carbon fiber bike frames is manufacturing method. Aluminum is cheap to machine and hydroform into efficient shapes, and carbon fiber can also be layed up into efficient shapes.
One advantage that adds to the potential lightness of aluminum and carbon fiber bike frames is manufacturing method. Aluminum is cheap to machine and hydroform into efficient shapes, and carbon fiber can also be layed up into efficient shapes.
> For mountain bikes, you will find almost zero steel bikes
Surly makes (only) steel mountain bikes, and I think there are approx. a... there's a lot of them out there. One reason is that they are inexpensive (relatively) and take a lot of abuse.
https://surlybikes.com/bikes/trail
Surly makes (only) steel mountain bikes, and I think there are approx. a... there's a lot of them out there. One reason is that they are inexpensive (relatively) and take a lot of abuse.
https://surlybikes.com/bikes/trail
> For a rigid road bike aluminum can definitely be made stronger and lighter,
Absolutely. What I meant was that while an aluminum bike frame can be lighter than steel, it's not as much lighter than steel than you'd expect. Steel bike frames tend to be only ~15% heavier than aluminum, not 50%.
Personally I bought a steel road because the difference in weight vs the aluminum alternative was small enough that I decided to go with the bike that looked nicer, and would last longer. Besides, I could use to lose a lot more weight than any bike ever could...
Absolutely. What I meant was that while an aluminum bike frame can be lighter than steel, it's not as much lighter than steel than you'd expect. Steel bike frames tend to be only ~15% heavier than aluminum, not 50%.
Personally I bought a steel road because the difference in weight vs the aluminum alternative was small enough that I decided to go with the bike that looked nicer, and would last longer. Besides, I could use to lose a lot more weight than any bike ever could...
> I could use to lose a lot more weight than any bike ever could...
Get a child trailer and load it up with groceries or cement! i tried it, the results are.. Surprising
Get a child trailer and load it up with groceries or cement! i tried it, the results are.. Surprising
Right now, top quality steel bike frames at the minimum bike weight allowed by the UCI are stronger than top quality carbon fibre bike frames of the same weight. Aluminum frames of the same weight would not be considered usable probably... (Pro cyclists would still use carbon fibre bikes because they can be made more aerodynamic).
That’s with a minimum weight imposed. Doesn’t change the fact that aluminum and titanium alloys generally have better strength-to-weight ratios than steel.
And fork is made out of steel (or carbon) even on aluminium bikes
Titanium is quite expensive. I don't know if it makes sense to compare it to mild steel and not compare it to fancier steel selections which are still much less expensive than titanium and also much easier to work.
AR500 has a HRC of 47, modulus of 220 GPa, and tensile strength of 1740 MPa. Ti-6Al-4V is 37, 113.8 GPa, and 880 MPa respectively. The AR500 costs less than half as much as the Ti, and is much easier to work (though obviously working will degrade the properties).
The titanium is super really light, however... so the choice of material will depend on how relatively important weight is vs size and how simple your geometry is such that the added difficulty in working with Ti doesn't add problems.
Obviously there are also other grades of Ti too, but I think the comparison generally holds: If you don't care about weight/mass there is a steel selection which will be stronger, cheaper, and easier to form.
If you do care a lot about weight, an aluminum alloy often comes out the winner unless you just don't care much about costs or have fatigue concerns.
AR500 has a HRC of 47, modulus of 220 GPa, and tensile strength of 1740 MPa. Ti-6Al-4V is 37, 113.8 GPa, and 880 MPa respectively. The AR500 costs less than half as much as the Ti, and is much easier to work (though obviously working will degrade the properties).
The titanium is super really light, however... so the choice of material will depend on how relatively important weight is vs size and how simple your geometry is such that the added difficulty in working with Ti doesn't add problems.
Obviously there are also other grades of Ti too, but I think the comparison generally holds: If you don't care about weight/mass there is a steel selection which will be stronger, cheaper, and easier to form.
If you do care a lot about weight, an aluminum alloy often comes out the winner unless you just don't care much about costs or have fatigue concerns.
Steel's strength varies by orders of magnitude depending on the alloy and heat treatment. It's an incredibly flexible family of materials. Some members of that family are far stronger than anything in the titanium family, e.g. 4340 steel has a nominal yield strength of >1800 MPa, compared to <1300 MPa for Ti 10-2-3.
We're not talking about exotic and expensive varieties of steel though. We're just talking about "general" or common steel and comparing it to unalloyed "common"/"general" titanium. Remember, Steel is itself an alloy, Titanium is an element.
If you start comparing Titanium alloys to Steel then the comparison gets even harder. Titanium alloys are in general stronger than steel as well as much lighter and more corrosion resistant.
If you start comparing Titanium alloys to Steel then the comparison gets even harder. Titanium alloys are in general stronger than steel as well as much lighter and more corrosion resistant.
> We're not talking about exotic and expensive varieties of steel though.
4340 steel isn't exotic. It's one of the most commonly used grades of steel out there, and it's much cheaper than titanium. There are steels out there with significant stronger yield strengths too. Meanwhile the highest yield strength of any Ti alloy is <1300MPa.
Titanium is still a really great material in certain applications. But it's not magic. You have to use it intelligently in the right application to get a benefit from it.
4340 steel isn't exotic. It's one of the most commonly used grades of steel out there, and it's much cheaper than titanium. There are steels out there with significant stronger yield strengths too. Meanwhile the highest yield strength of any Ti alloy is <1300MPa.
Titanium is still a really great material in certain applications. But it's not magic. You have to use it intelligently in the right application to get a benefit from it.
The family of materials we call steel is so fantastic, it almost a shame it’s so ubiquitous that we take it for granted. If it were invented today the front page of HN would be loaded with stories of this miracle material.
The newest generation most advanced spaceships are made from steel, see Starship.
When you go to both maximum cold (cryo fuel), and you go to maximum (reentry heat) then steel is amazing.
Aluminum would turn to butter on reentry, it would require a massive amount of heat shielding. Titanium alloys would have same issue.
Titanium alloy also become to brittle in deep cryo.
So steel beats everything in this demanding application. Its amazing.
When you go to both maximum cold (cryo fuel), and you go to maximum (reentry heat) then steel is amazing.
Aluminum would turn to butter on reentry, it would require a massive amount of heat shielding. Titanium alloys would have same issue.
Titanium alloy also become to brittle in deep cryo.
So steel beats everything in this demanding application. Its amazing.
Pure elemental titanium has much less desirable material properties than various titanium alloys which are what you encounter most commonly. It is very uncommon to encounter elemental titanium outside of a chemistry lab.
Grade 1 is still pretty common for ultralight backpacking items like pots and pans due to its ductility.
Thats cool! I didnt know there were specific common applications where grade 1 would be desirable compared to the stronger alloys available.
IIRC you can buy titanium foil that you can just make stuff out of at home.
I have some titanium crafting wire. Should be easy to find on Amazon or similar. It's a little surreal - looks similar to a roll of steel wire, but feels as lightweight as PLA. Basically the real-world version of mithril.
So called “mild steel” would be far more accurately called “iron”, the carbon content is insignificant.
The carbon content of mild steel is low but not insignificant. Pure wrought iron [0] is a dream to forge and it has a huge grain structure. It's more ductile than mild steel but it's also not as hardenable or tough as mild steel [1]. That little bit of carbon in mild steel makes a big difference.
[0] I mean real wrought iron -- the almost 100% elemental stuff -- like the Eiffel tower is made of. This is practically unobtainable today. The "wrought iron" you commonly see for sale nowadays is always mild steel. And "cast iron" is actually very high carbon steel, not iron. Cast iron so high in carbon that it's brittle and cannot be forged or easily welded.
[1] It's a myth that mild steel cannot be hardened. With a proper wetting agent added to the quench, you can harden it significantly.
[0] I mean real wrought iron -- the almost 100% elemental stuff -- like the Eiffel tower is made of. This is practically unobtainable today. The "wrought iron" you commonly see for sale nowadays is always mild steel. And "cast iron" is actually very high carbon steel, not iron. Cast iron so high in carbon that it's brittle and cannot be forged or easily welded.
[1] It's a myth that mild steel cannot be hardened. With a proper wetting agent added to the quench, you can harden it significantly.
Wrought iron and mild steel are more or less functionally equivalent. One other reason why cast iron is so brittle is because it contains quite a bit of silicon.
> We're not talking about exotic and expensive...
> "general" or common steel and "common"/"general" titanium
Why would you compare 'trash-quality' steel vs exotic and expensive material like Titanium?
That does not make any sence.
> "general" or common steel and "common"/"general" titanium
Why would you compare 'trash-quality' steel vs exotic and expensive material like Titanium?
That does not make any sence.
Wikipedia:
>4340 steel is an ultra-high strength steel
https://en.wikipedia.org/wiki/4340_steel
The alloy composition calls for 0.2-0.3% molybdenum and expects accuracy to within a few per mille for ten elements. Moly is considered so important that there are entire towns in the United States established to mine it to secure the military supply chain.
>4340 steel is an ultra-high strength steel
https://en.wikipedia.org/wiki/4340_steel
The alloy composition calls for 0.2-0.3% molybdenum and expects accuracy to within a few per mille for ten elements. Moly is considered so important that there are entire towns in the United States established to mine it to secure the military supply chain.
Is this true? From the Wikipedia article, the two mines that produce molybdenum as the main product are the two in CO, Henderson and Climax. They have no towns associated with them. Climax is near Leadville, but Leadville existed as a mining town before molybdenum was being mined at any scale. The other mine isn't close to any town that has more than a trailer park of people.
The others mine molybdenum as a byproduct of copper. I guess you could say the Bagdad mine has a company town, but it wasn't made to secure the military supply chain 140 year ago.
The others mine molybdenum as a byproduct of copper. I guess you could say the Bagdad mine has a company town, but it wasn't made to secure the military supply chain 140 year ago.
There are definitely steels that lose out to grade 5 Titanium. There are also steels that beat all Titanium grades. It's not so simple to say steel is stronger then Titanium. Some steels are stronger then titanium. Some Titanium grades are stronger then Some steels.
The article mentions that the Soviet Union had lots of titanium ore, and also that it was heavily used in the A-12/SR-71 family of aircraft.
I remember reading elsewhere that the CIA set up a bunch of front operations across the world to buy titanium (or maybe titanium ore) from the USSR without them finding out what it was being used for. They didn't want the "Ship to:" part of the order form reading "Lockheed Skunkworks, Burbank Califoria". Heh.
I remember reading elsewhere that the CIA set up a bunch of front operations across the world to buy titanium (or maybe titanium ore) from the USSR without them finding out what it was being used for. They didn't want the "Ship to:" part of the order form reading "Lockheed Skunkworks, Burbank Califoria". Heh.
Elsewhere would of course be the excellent "Skunk Works: A Personal Memoir of My Years at Lockheed" by Ben Rich.
Highly reccomended and goes into further engineering and design challenges of the RS-71 Blackbird and its titanium construction.
Highly reccomended and goes into further engineering and design challenges of the RS-71 Blackbird and its titanium construction.
There's an interesting story about trading Boeing aircraft design knowledge for Soviet titanium design knowledge during the cold war. https://www.smithsonianmag.com/air-space-magazine/the-titani...
Huge fan of Titanium.
If only we could find a cheap way to get the metal out of titanium dioxide. Like a Haber process-level breakthrough.
Then we could start replacing steel with titanium in many applications. Think entire freight trains, cargo ships, containers, cars, trucks, tractors -- all that heavy steel replaced by titanium alloys.
Enormous quantities of fuel and energy saved by lower density and higher strength. In many applications, it would likely make stainless steel obsolete.
Trillions of dollars of value may be locked up in such a breakthrough.
If only we could find a cheap way to get the metal out of titanium dioxide. Like a Haber process-level breakthrough.
Then we could start replacing steel with titanium in many applications. Think entire freight trains, cargo ships, containers, cars, trucks, tractors -- all that heavy steel replaced by titanium alloys.
Enormous quantities of fuel and energy saved by lower density and higher strength. In many applications, it would likely make stainless steel obsolete.
Trillions of dollars of value may be locked up in such a breakthrough.
I think it could be one of those 'grass-is-greener' scenarios. Steel is really nice to work with. It's strong and elastic and you can do all sorts of things to alter its properties, like even in a home shop.
Titanium always looks really hard to work with, just from the few times I've seen youtube types get some into their lathe chucks.
Would the added (in some ways just different) performance make up the difference? No idea. I mean, would people use so much aluminium if it wasn't straightforward to extrude it into interesting shapes? I don't think I would.
The straight characteristics of a material are one thing: what you can actually do with it are another.
Titanium always looks really hard to work with, just from the few times I've seen youtube types get some into their lathe chucks.
Would the added (in some ways just different) performance make up the difference? No idea. I mean, would people use so much aluminium if it wasn't straightforward to extrude it into interesting shapes? I don't think I would.
The straight characteristics of a material are one thing: what you can actually do with it are another.
https://en.wikipedia.org/wiki/Titanium_alloys
Looks like alloys are much more mallable, while losing almost none of the qualities of pure titanium.
Also: Go nukkular, high-temperature to be specific.
Looks like alloys are much more mallable, while losing almost none of the qualities of pure titanium.
Also: Go nukkular, high-temperature to be specific.
maybe if the blast furnace hadn't been invented nearly a thousand years ago we wouldn't be so familiar with the techniques that work well on steel
That's true. On the other hand, people have been working with flint for longer than there have been people, and it remains fiendishly hard to make anything with it.
that's maybe an exaggeration; people still make buildings out of flint, they make it into perfect spheres for ball mills, and when flintlock was the firing mechanism of choice, they shaped flints for rifles out of it. the main reason we don't have a lot of flint goods around is that, aside from its edge-forming powers, it doesn't have great properties: it's brittle, nonconductive and not all that pretty, much like unglazed fired clay
you can grind it into whatever shape you want if you're careful about silicosis
you can grind it into whatever shape you want if you're careful about silicosis
The ground is covered with flint arrowheads in various parts of TX that I’ve visited and/or inhabited. It’s really hard for me to imagine Indians crafting so many of them if it were that hard to work with.
They had no other viable options. It is hard to work with.
[deleted]
That's why I said titanium alloys specifically. With such a large-scale industrial transformation, definitely many alloys would be explored, to fit the needs of new industries. We don't use pure iron for any serious applications either.
Fatigue is why we use steel for everything, no other alloys have the practical strength and infinite life.
You are correct in that steel is harder and stiffer than titanium. Steel is also more re-usable, smelt-able than titanium.
However, when it comes to fatigue (which I assume, you are referring to fracture strain) titanium has a significant edge. The fracture strain for steel is roughly 15%, but for titanium alloys, it often reaches and exceeds 50%.
I don't say this to contradict you, but to point out that as with most things in life, "it depends".
Source: https://www.ulbrich.com/blog/titanium-versus-steel-a-battle-....
However, when it comes to fatigue (which I assume, you are referring to fracture strain) titanium has a significant edge. The fracture strain for steel is roughly 15%, but for titanium alloys, it often reaches and exceeds 50%.
I don't say this to contradict you, but to point out that as with most things in life, "it depends".
Source: https://www.ulbrich.com/blog/titanium-versus-steel-a-battle-....
A better argument for steel is it requires 5-10 kwhr/kg to produce vs 60kwhr/kg for aluminum and 250kwhr/kg for titanium. So for the same energy you get 6 times more steel than aluminum and 25 times more than titanium. Which seems to say when the properties of steel are acceptable it's the cheaper option.
https://solar.lowtechmagazine.com/2009/06/how-much-energy-do...
https://solar.lowtechmagazine.com/2009/06/how-much-energy-do...
Like steel, titanium alloys have a distinct non-zero fatigue limit, and thus can be engineered to have infinite fatigue lives. Though the exact details differ and steel or titanium can be better depending on exactly what the conditions are.
Metalysis have made claims like this:
https://metalysis.com/
Based on this tech: https://en.m.wikipedia.org/wiki/FFC_Cambridge_process
Still waiting for my titanium girders though...
Based on this tech: https://en.m.wikipedia.org/wiki/FFC_Cambridge_process
Still waiting for my titanium girders though...
This is cool. Thanks!
In my mind, this is what real technology entrepreneurship looks like. As opposed to the latest crypto or social media thing.
In my mind, this is what real technology entrepreneurship looks like. As opposed to the latest crypto or social media thing.
> Then we could start replacing steel with titanium in many applications.
The world's production of stainless steel is growing almost exponentially and we are replacing many applications or ordinary steel with stainless. Every year millions of tons of steel are lost to rust.
Its a gigsntic shift noone is noticing
The world's production of stainless steel is growing almost exponentially and we are replacing many applications or ordinary steel with stainless. Every year millions of tons of steel are lost to rust.
Its a gigsntic shift noone is noticing
Resting next to me is a titanium ring, it is extremely light, resistant to ambient temp change, and is usually cool to the touch. It cost $15 or so. It wears in a really beautiful way, aging like it's enjoying itself.
On my finger is a tungsten carbide ring, it's extremely dense (that of gold, slightly heavier than uranium), and has a lot of interesting properties. It's warmed quickly by my fingers, and rings the most beautiful tone when I strike it with some bar stock of AI.
Wolfram has been a very nice metal in my life, I wish it was more common, and would love to try to add some knurling to it.
On my finger is a tungsten carbide ring, it's extremely dense (that of gold, slightly heavier than uranium), and has a lot of interesting properties. It's warmed quickly by my fingers, and rings the most beautiful tone when I strike it with some bar stock of AI.
Wolfram has been a very nice metal in my life, I wish it was more common, and would love to try to add some knurling to it.
I wear a titanium ring too and keep my real one safely locked away. It’s an incredible metal that I proudly wear around. Mine cost about the same.
I also have a titanium pocketknife (James Brand), carabiner, keyrings, pens, camera (fujifilm makes a few), and some beloved snow peak dishes. And the silly titanium iPhone. It’s such a great metal to make things to carry with.
I also have a titanium pocketknife (James Brand), carabiner, keyrings, pens, camera (fujifilm makes a few), and some beloved snow peak dishes. And the silly titanium iPhone. It’s such a great metal to make things to carry with.
It’s not that great for blades as it doesn’t retain its edge as well as steel and is harder to sharpen.
It’s usually the frame and sides / scales that are made of titanium, never the blade afaik.
Except maybe in some multitool keyring single piece doohickeys, but it’s not expected to cut anything beside the tape on your packaging.
Except maybe in some multitool keyring single piece doohickeys, but it’s not expected to cut anything beside the tape on your packaging.
Titanium so widely desirable for knife scales because of not only its strength to weight benefits but also interesting finishes that can be applied for instance anodization can give incredibly beautiful iridescent colors in a wide spectrum of potential colors and tones. I dont know how interested you are in modding your pocket knife but there are several very talented people that can do just stunning colorful and textural finishes on titanium.
Where can I learn more about this?
Do you mind sharing where you got the titanium keyrings and carabiners?
I've been searching forever for decent keyrings. There's a few carabiners (though the titanium ones are hard to find there too, and usually covered in obnoxious branding). But keyrings especially seem to be an under-served market. There's either (1) the usual mass-produced, flimsy, cheap garbage, or (2) something tougher and more expensive, but covered in branding.
I've settled with (2) for now (though it's not even titanium), but it'd be nice to not have to look at a giant billboard every time I pull out my keys.
I've been searching forever for decent keyrings. There's a few carabiners (though the titanium ones are hard to find there too, and usually covered in obnoxious branding). But keyrings especially seem to be an under-served market. There's either (1) the usual mass-produced, flimsy, cheap garbage, or (2) something tougher and more expensive, but covered in branding.
I've settled with (2) for now (though it's not even titanium), but it'd be nice to not have to look at a giant billboard every time I pull out my keys.
Yes! I ordered these: https://www.amazon.com/Outus-Titanium-Rings-Split-Pack/dp/B0...
My super-scientific "is titanium" test involved trying to get a fridge magnet to stick to them. it won't, and a normal keyring will. Yes, that risks it being aluminum. Other reviews state they put one against their sanding machine and got white sparks which was an additional positive sign.
If you want to confidently get titanium, these: https://thejamesbrand.com/products/titanium-keyring
They also make the carabiner I mentioned: https://thejamesbrand.com/products/the-mehlville?variant=312...
And here's a beer bottle opener to complete your collection: https://thejamesbrand.com/products/the-tjb-bottle-opener-tit...
My super-scientific "is titanium" test involved trying to get a fridge magnet to stick to them. it won't, and a normal keyring will. Yes, that risks it being aluminum. Other reviews state they put one against their sanding machine and got white sparks which was an additional positive sign.
If you want to confidently get titanium, these: https://thejamesbrand.com/products/titanium-keyring
They also make the carabiner I mentioned: https://thejamesbrand.com/products/the-mehlville?variant=312...
And here's a beer bottle opener to complete your collection: https://thejamesbrand.com/products/the-tjb-bottle-opener-tit...
Titanium anodizes very easily with a 9V battery and a wet paper towel. It’s a quick, and easy to way to test for titanium.
I have one too. It’s not my favorite to wear because it has zero heft. It’s unsubstantial and has a strange plasticky somewhat sticky feel. I plan on replacing it with gold. I can’t complain about the price though - they came in a box of 3.
I have a nickel allergy so titanium is my first port of call for jewellery, though my wedding ring is zirconium and some of my old, pre-allergy stuff is now plated with rhodium.
niobium is a happy metal for nickel allergies. feels like tanium and doesn't trigger allergies.
Source - my wife breaks out from nickel in jean rivets but niobium is good enough for piercings
Source - my wife breaks out from nickel in jean rivets but niobium is good enough for piercings
Useful info, thanks!
I can't help but recall Steve Jobs introducing the PowerBook G4 Titanium:
> "Titanium! It's made out of titanium! Like the spy planes! This is an incredible material, it's stronger than steel yet lighter than aluminium."
https://youtu.be/bNHkrnU77m0?t=92
> "Titanium! It's made out of titanium! Like the spy planes! This is an incredible material, it's stronger than steel yet lighter than aluminium."
https://youtu.be/bNHkrnU77m0?t=92
I could see a day when titanium laptops return. Apple has invested in the some of the best mass machining in the world. I wonder what it’d look like sandblasted like their laptops and with their new coatings.
I miss the short "how it's made" videos that used to be in every single Apple production introduction (e.g. https://www.youtube.com/watch?v=GQnr-kfuVdQ).
There was a blog called "Atomic Delights" that would explain the manufacturing processes featured in the videos. Found it super interesting, especially considering the challenge of shipping products at Apple level volumes.
A MBP with the natural titanium finish as seen in the iPhone 15 Pro would be fantastic.
There was a blog called "Atomic Delights" that would explain the manufacturing processes featured in the videos. Found it super interesting, especially considering the challenge of shipping products at Apple level volumes.
A MBP with the natural titanium finish as seen in the iPhone 15 Pro would be fantastic.
> I could see a day when titanium laptops return.
I don't get it. I was issued a metal macbook once. I had to buy a plastic case for it, because the bare metal scratched my fingernails.
Why would we want a hard metal case instead of a soft plastic one?
I don't get it. I was issued a metal macbook once. I had to buy a plastic case for it, because the bare metal scratched my fingernails.
Why would we want a hard metal case instead of a soft plastic one?
> because the bare metal scratched my fingernails.
Nice multi-purpose titanium laptop. You can even trim your fingernails on the same!
Nice multi-purpose titanium laptop. You can even trim your fingernails on the same!
It would be less effective than a file, since there's just the one point on the sharp edge of the laptop.
Most people are not looking to scuff up the face of their fingernails, which is what happens when you handle such a laptop naturally.
Most people are not looking to scuff up the face of their fingernails, which is what happens when you handle such a laptop naturally.
Plastic cases flexing can damage the electronics inside hence most of the Apple stuff being metal.
It doesn't seem to cause problems for any other manufacturer. I'm using a plastic-cased Dell laptop as we speak.
If plastic cases bore any significant risk of damaging the electronics, someone would probably have noticed that by now.
If plastic cases bore any significant risk of damaging the electronics, someone would probably have noticed that by now.
Wasn't one of the major problems that Titanium doesn't play well with Wifi? The TiBook predated built-in wifi, and I thought one of the reason to shift to Aluminum was wifi performance.
I had IBM notebook with titanium case (before it became Lenovo)
Almost everything about the article is wrong, oversimplified, or misleading.
Take this paragraph, for instance:
> But despite its abundance, it's only recently that civilization has been able to use titanium as a metal (titanium dioxide has been in use somewhat longer as a paint pigment). Because titanium so readily bonds with oxygen and other elements, it doesn’t occur at all in metallic form in nature. One engineer described titanium as a “streetwalker," because it will pick up anything and everything. While copper has been used by civilization since 7000 BC, and iron since around 3000 BC, titanium wasn’t discovered until the late 1700s, and wasn’t produced in metallic form until the late 19th century.
As this is basically a bunch of bullet points in paragraph form, it'll be easier to handle if we break it down:
> But despite its abundance, it's only recently that civilization has been able to use titanium as a metal (titanium dioxide has been in use somewhat longer as a paint pigment).
The same also applies to aluminum, magnesium, nickel, etc.
> Because titanium so readily bonds with oxygen and other elements, it doesn’t occur at all in metallic form in nature.
The same also applies to aluminum, magnesium, and even iron. (I mean, there's some meteoric iron, but it's very rare.) Pure metals are very rare in nature. What distinguishes iron and copper from aluminum and titanium is the energy required to split the oxide into metal.
> One engineer described titanium as a “streetwalker," because it will pick up anything and everything.
Titanium is not more reactive than aluminum and it's far less reactive than magnesium. In fact, it's slightly less reactive than iron overall. (i.e., more chemically stable under normal conditions and in contact with common acids.)
> While copper has been used by civilization since 7000 BC, and iron since around 3000 BC, titanium wasn’t discovered until the late 1700s, and wasn’t produced in metallic form until the late 19th century.
This has everything to do with the temperature required to separate the metal from the oxygen atoms binding it, and nothing to do with anything else. What's more, it applies even more strongly to aluminum, which was discovered in 1825 -- three decades after the discovery of titanium. (1791.) So there's absolutely nothing unique about titanium in this regard.
I could go on. But basically this is an "I hecking love science" article that barely scratches the surface of the subject -- and still manages to be subtly misleading.
Take this paragraph, for instance:
> But despite its abundance, it's only recently that civilization has been able to use titanium as a metal (titanium dioxide has been in use somewhat longer as a paint pigment). Because titanium so readily bonds with oxygen and other elements, it doesn’t occur at all in metallic form in nature. One engineer described titanium as a “streetwalker," because it will pick up anything and everything. While copper has been used by civilization since 7000 BC, and iron since around 3000 BC, titanium wasn’t discovered until the late 1700s, and wasn’t produced in metallic form until the late 19th century.
As this is basically a bunch of bullet points in paragraph form, it'll be easier to handle if we break it down:
> But despite its abundance, it's only recently that civilization has been able to use titanium as a metal (titanium dioxide has been in use somewhat longer as a paint pigment).
The same also applies to aluminum, magnesium, nickel, etc.
> Because titanium so readily bonds with oxygen and other elements, it doesn’t occur at all in metallic form in nature.
The same also applies to aluminum, magnesium, and even iron. (I mean, there's some meteoric iron, but it's very rare.) Pure metals are very rare in nature. What distinguishes iron and copper from aluminum and titanium is the energy required to split the oxide into metal.
> One engineer described titanium as a “streetwalker," because it will pick up anything and everything.
Titanium is not more reactive than aluminum and it's far less reactive than magnesium. In fact, it's slightly less reactive than iron overall. (i.e., more chemically stable under normal conditions and in contact with common acids.)
> While copper has been used by civilization since 7000 BC, and iron since around 3000 BC, titanium wasn’t discovered until the late 1700s, and wasn’t produced in metallic form until the late 19th century.
This has everything to do with the temperature required to separate the metal from the oxygen atoms binding it, and nothing to do with anything else. What's more, it applies even more strongly to aluminum, which was discovered in 1825 -- three decades after the discovery of titanium. (1791.) So there's absolutely nothing unique about titanium in this regard.
I could go on. But basically this is an "I hecking love science" article that barely scratches the surface of the subject -- and still manages to be subtly misleading.
> The same also applies to aluminum, magnesium, nickel, etc.
the oxides of aluminum, magnesium, and nickel were not in use as paint pigments
> What distinguishes iron and copper from aluminum and titanium is the energy required to split the oxide into metal. (...) Titanium is not more reactive than aluminum
the particularly relevant issue here, as i understand it, is that titanium has a stable carbide, which prevents you from reducing it carbothermically; you end up with titanium carbide instead of titanium metal. aluminum's carbide is unstable even in water, while iron's carbide is mechanically strong but still easy to reduce to iron with air. copper's carbide is poorly characterized and even more unstable, and it even occurs native
there are other things that titanium reacts more strongly with than aluminum does. titanium tetrachloride, for example, which is mentioned in the article, isn't a mere salt like normal chlorides; it's a volatile fuming liquid, because titanium forms covalent bonds with the chlorine like a motherfucking nonmetal. you can argue about whether this makes it more or less reactive than aluminum in this context; the reaction produces more energy per metal atom but less energy per chlorine atom
this kind of dirty trick is why titanium wasn't isolated until decades after the creation of metallic calcium, sodium, potassium, aluminum, and even the isolation of some of the rare earths
so i think the characterization in the article is fair
the oxides of aluminum, magnesium, and nickel were not in use as paint pigments
> What distinguishes iron and copper from aluminum and titanium is the energy required to split the oxide into metal. (...) Titanium is not more reactive than aluminum
the particularly relevant issue here, as i understand it, is that titanium has a stable carbide, which prevents you from reducing it carbothermically; you end up with titanium carbide instead of titanium metal. aluminum's carbide is unstable even in water, while iron's carbide is mechanically strong but still easy to reduce to iron with air. copper's carbide is poorly characterized and even more unstable, and it even occurs native
there are other things that titanium reacts more strongly with than aluminum does. titanium tetrachloride, for example, which is mentioned in the article, isn't a mere salt like normal chlorides; it's a volatile fuming liquid, because titanium forms covalent bonds with the chlorine like a motherfucking nonmetal. you can argue about whether this makes it more or less reactive than aluminum in this context; the reaction produces more energy per metal atom but less energy per chlorine atom
this kind of dirty trick is why titanium wasn't isolated until decades after the creation of metallic calcium, sodium, potassium, aluminum, and even the isolation of some of the rare earths
so i think the characterization in the article is fair
> the oxides of aluminum, magnesium, and nickel were not in use as paint pigments
Aluminum oxides were used as a pigment, predominantly in blue (cobalt aluminum oxide) but also in white.
In any case, the dominant white dyes of the Early Modern period -- and prior periods -- were lead based. The presence of TiO2-based pigments is actually one good way to identify a modern forgery.
> the particularly relevant issue here, as i understand it, is that titanium has a stable carbide
This turned out to be solvable via calciothermic or magnesiothermic reduction -- which is now effectively the go-to method for just about everything that can't be reduced with carbon. All titanium dioxide reduction processes demand quite a lot of energy, though; more than aluminum and far more than iron.
Aluminum oxides were used as a pigment, predominantly in blue (cobalt aluminum oxide) but also in white.
In any case, the dominant white dyes of the Early Modern period -- and prior periods -- were lead based. The presence of TiO2-based pigments is actually one good way to identify a modern forgery.
> the particularly relevant issue here, as i understand it, is that titanium has a stable carbide
This turned out to be solvable via calciothermic or magnesiothermic reduction -- which is now effectively the go-to method for just about everything that can't be reduced with carbon. All titanium dioxide reduction processes demand quite a lot of energy, though; more than aluminum and far more than iron.
people don't make titanium via calciothermic or magnesiothermic reduction of the ore, i don't know why
the magnesiothermic reduction is the actual reduction step of the kroll process, though
the magnesiothermic reduction is the actual reduction step of the kroll process, though
The article may be an oversimplification, but your comment is an equal oversimplification. There are many environmental conditions that need to be assumed when comparing reactivity.
For instance, if you have pure Titanium, pure Magnesium, pure aluminum in a vacuum at room temperature and proceed to introduce oxygen, you get the following reactions (simplified elemental chemical reactions, the Enthalpy of formation is what is important here):
Ti + O2 -> TiO2 (Std. Enthalpy of formation is -945kJ/mol)
Mg + O -> MgO (Std. Enthalpy of formation is -601kJ/mol)
4Al + 3O2 -> 2 Al2O3 (Std. Enthalpy of formation is -1675kJ/mol)
As a result, aluminum is most reactive, followed by titanium, then magnesium.
This is the reason why aluminum is used in solid rocket motors and various other explosive devices.
Under different conditions, these numbers may change: for instance a reaction with water instead of air may yield different enthalpies. At quick glance in water, titanium is actually least reactive when compared to aluminum and magnesium.
For instance, if you have pure Titanium, pure Magnesium, pure aluminum in a vacuum at room temperature and proceed to introduce oxygen, you get the following reactions (simplified elemental chemical reactions, the Enthalpy of formation is what is important here):
Ti + O2 -> TiO2 (Std. Enthalpy of formation is -945kJ/mol)
Mg + O -> MgO (Std. Enthalpy of formation is -601kJ/mol)
4Al + 3O2 -> 2 Al2O3 (Std. Enthalpy of formation is -1675kJ/mol)
As a result, aluminum is most reactive, followed by titanium, then magnesium.
This is the reason why aluminum is used in solid rocket motors and various other explosive devices.
Under different conditions, these numbers may change: for instance a reaction with water instead of air may yield different enthalpies. At quick glance in water, titanium is actually least reactive when compared to aluminum and magnesium.
You can make a general benchmark assumption, e.g. in the Reactivity Series:
https://en.wikipedia.org/wiki/Reactivity_series
So from a high enough vantage point, Ti is very slightly less reactive than Al, less reactive than Mg, and not too far from Fe. A far cry from being "a streetwalker" of a metal.
https://en.wikipedia.org/wiki/Reactivity_series
So from a high enough vantage point, Ti is very slightly less reactive than Al, less reactive than Mg, and not too far from Fe. A far cry from being "a streetwalker" of a metal.
to make a fair comparison here, you need to normalize per mole of metal. these enthalpies of formation are reported per mole of oxide, but there's twice as much Al per mole of Al2O3 than Ti in TiO2.
Great overview: Titanium production technology essentially “willed into existence” by the US government (mainly the military branches) but now critical in health care for implants that embed with bone and that do not induce rejection.
Love titanium, something so cool about it. It’s like steel with no downsides. I’ve got 5 ti bikes and a few ti watches, one of my favorite pieces though is my snow peak double wall titanium mug.
Do your bikes have carbon forks or TI? when I looked at TI bikes for fun in the past, the carbon forks surprised me, seemed like that should have been titanium too. How has your mug held up? Has it been compatibly durable compared to steel vacuum mugs? Snow peak makes great products but leans more lightweight than durable from my experience with their dishware
Titanium needs to be in a bigger tube with thinner walls to take advantage of the properties compared to steel - the very first titanium bicycles used the available surplus tubing from defense/aeronautics industry that was close to steel bicycle tubing size and were notably not great until they used slightly bigger tubing and better titanium alloys. Forks have a couple of design features that make it hard to work with titanium tubing, the height from bottom of headtube to where the top of the tire is has to have extra space for clearance or a tiny object or some mud will clog up the fork pretty quickly or cause an immediate stop in front wheel rotation, and that part of the fork has to be extremely stiff. Some of of the first carbon forks had a titanium steerer tube for a minimal weight saving and to make it easier to work with the stem attachment system. Several equipment changes to this part of the bicycle have come about in the last couple of decades to accommodate carbon fiber more easily. The market for titanium was just too niche by comparison to make those changes necessary.
This is super cool, I didn't realize the reason would be so complex. Thanks for explaining!
It's been done but the cost is very high compared to other materials because of the amount of specialized labor and only boutique builders offer one, the legs are really fat so it has poor aerodynamics so it's only suitable for off-road as a drop in replacement for a bicycle frame built for a suspension fork to account for the crown to tire distance and almost everyone has switched to suspension off-road. I've ridden some of the cheaper titanium forks and they flexed so much I did not feel comfortable riding them but have heard even the expensive ones flex quite a bit.
One does actually (https://bearclawbicycleco.com/titanium-gravel-fork/). Mug looks practically brand new several years later.
Finally a titanium stan thread! Due to skin allergies/sensitivities, the only material I can wear for watches seems to be titanium. Luckily the market for them are mostly all stylish and functional. And they're so light! It's like I'm wearing another piece of clothing on my wrist that's cold and tells me the time.
Snow Peak's titanium spork is awesome as well. I got two and use one for my regular meals and the other I EDC in a cargo pocket for use away from home.
What makes the mug particularly good? Always interested in something to improve coffee and recently broke my favourite one.
Tea, especially green tea, in a titanium mug is, in my experience, utterly gross.
Maybe anodized titanium would work better? I don’t know what the chemistry behind the problem is, but even stainless steel kills green tea after a while.
Maybe anodized titanium would work better? I don’t know what the chemistry behind the problem is, but even stainless steel kills green tea after a while.
It’s super light, about the same weight as single wall stainless cup. The mouthfeel is nice, hot coffee doesn’t make the titanium feel as hot as steel gets and the feel is more similar to ceramic than stainless steel. It cleans up really nice and truly doesn’t stain. I even used a dc transformer to do some custom anodizing on mine and it looks really cool.
I've got a Ti double-walled mug from Snow Peak that I use a lot around the house. The big strengths are light weight, near indestructability, and a cool Ti functional aesthetic. It's double-walled and holds heat well, but I prefer the "mouth feel" of ceramic or glass when drinking coffee, so I don't use it much for coffee.
I've got one myself. For only a bit more weight (~70g) than single-walled aluminum mug (~60g), Snow Peak can put two walls, making the mug insulated.
Though it's heavier than an insulated plastic mug, and _way_ more expensive.
Though it's heavier than an insulated plastic mug, and _way_ more expensive.
Titanium is not good for flavor, its good for strength to weight ratio for people concerned with weight (think EDC, ultralight, etc)
Lightweight for camping. I have a titanium flask that was engraved by a guy on YouTube.
I have a titanium chainmail shirt: https://www.etsy.com/listing/505806057/titanium-chainmaille-... (me in 2nd pic)
It weighs just 6.6 lbs. (the page says 6.5 but I had to have him add a bit cause I got too swole in the lats a couple of years ago.)
It's fun to have someone try it on then watch them struggle as they can't figure out how to get it off lol
If you bend over and stick your arms down it basically slide off on its own.
What's really interesting is the ringing sound it makes when you play with it or move around wearing it, it's a noticibly higher pitch than steel is.
I also have a necklace/spacepen lanyard, wallet chain, and coif made of titanium by Bim also. My keyrings and bottle opener are also titanium. It's such a cool metal. Kind of a pity it makes a very poor knife blade. Speaking of: I also replaced the screws and hinges of my bespoke Benchmade knife with titanium ones, because why not?
A bit obsessed as you can tell.
tl;dr I have a mithril shirt
It weighs just 6.6 lbs. (the page says 6.5 but I had to have him add a bit cause I got too swole in the lats a couple of years ago.)
It's fun to have someone try it on then watch them struggle as they can't figure out how to get it off lol
If you bend over and stick your arms down it basically slide off on its own.
What's really interesting is the ringing sound it makes when you play with it or move around wearing it, it's a noticibly higher pitch than steel is.
I also have a necklace/spacepen lanyard, wallet chain, and coif made of titanium by Bim also. My keyrings and bottle opener are also titanium. It's such a cool metal. Kind of a pity it makes a very poor knife blade. Speaking of: I also replaced the screws and hinges of my bespoke Benchmade knife with titanium ones, because why not?
A bit obsessed as you can tell.
tl;dr I have a mithril shirt
Curious how durable a Ti shirt would be. Could it save you walking down a dark alley at night?
Looks like they're just butted rings, so you're relying on the rididity of each ring to resist opening up.
Welded or rivited rings would be much more robust. Especially vs piercing weapons, like arrows or fighting knives.
But much more expensive.
Welded or rivited rings would be much more robust. Especially vs piercing weapons, like arrows or fighting knives.
But much more expensive.
I owned a carbon road bike - which unfortunately I wrecked due to a problem with my chain. I then bought a used titanium bike, and I have peace of mind since then. It might be just a psychological effect - but it just feels good to have a bike frame that's extremely difficult to destroy.
Titanium is a wonderful material but I think many people are way more idealistic about how great it is than it is in reality. In nearly every category other than weight constraints steel still wins out and is so much easier to work with.
Great article!
Sad it's so USA-centric.
It would be great to read "Soviet part" of titanium
The real story now is how China centric it is - a lot of the worlds machining capabilities for it are still only there.
A little info in the subject.
https://history.stackexchange.com/questions/28152/when-and-h...
https://history.stackexchange.com/questions/28152/when-and-h...
How can titanium be both a "streetwalker" and "incredibly corrosion-resistant"?
same as aluminum, it immediately forms a hard and adherent oxide layer upon exposure to air or especially water
There is evidence titanium may be the cause of the rare disease yellow nail syndrome: https://en.wikipedia.org/wiki/Yellow_nail_syndrome
study ref: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3176400/
study ref: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3176400/
Of possible interest
Tales About Metals
https://archive.org/details/VenetskyTalesAboutMetals
On Rare and Scattered Metals
https://archive.org/details/OnRareAndScatteredMetalsTalesAbo...
Tales About Metals
https://archive.org/details/VenetskyTalesAboutMetals
On Rare and Scattered Metals
https://archive.org/details/OnRareAndScatteredMetalsTalesAbo...
Great article!
>"The earth contains a lot of titanium - it’s the ninth most abundant element in the earth’s crust. By mass, there’s more titanium in the earth’s crust than carbon by a factor of nearly 30, and more titanium than copper by a factor of nearly 100."
>"Titanium was nearly as strong as stainless steel, but weighed 40% less."
Consider Steel I-Beams, used in construction:
https://en.wikipedia.org/wiki/I-beam
Observation: If the workability difficulties of Titanium could be solved, at scale -- then not Steel, but Titanium I-Beams -- could be produced, en masse...
If this could be done cheaply enough, then, in the future, Titanium I-Beams -- produced in the U.S.A. -- could retake the worldwide market for construction I-Beams that was historically lost when other countries started producing Steel I-Beams cheaper than the U.S. did...
Anyway, an excellent article!
>"The earth contains a lot of titanium - it’s the ninth most abundant element in the earth’s crust. By mass, there’s more titanium in the earth’s crust than carbon by a factor of nearly 30, and more titanium than copper by a factor of nearly 100."
>"Titanium was nearly as strong as stainless steel, but weighed 40% less."
Consider Steel I-Beams, used in construction:
https://en.wikipedia.org/wiki/I-beam
Observation: If the workability difficulties of Titanium could be solved, at scale -- then not Steel, but Titanium I-Beams -- could be produced, en masse...
If this could be done cheaply enough, then, in the future, Titanium I-Beams -- produced in the U.S.A. -- could retake the worldwide market for construction I-Beams that was historically lost when other countries started producing Steel I-Beams cheaper than the U.S. did...
Anyway, an excellent article!
Machining titanium is possible, but remains difficult. It's slow and you go through a lot of cutters.
Now this is just showing off.[1] Daishin and Open Mind started with a 60 kilogram cylinder of titanium and milled a very detailed crown out of it. 300 hours of CNC machining time on a very good 5-axis mill. Most of the metal ends up as scrap.
The software for this is called HyperMill. If you have to ask how much it costs, you can't afford it.
[1] https://www.youtube.com/watch?v=Bqv5SjC4s6w
Now this is just showing off.[1] Daishin and Open Mind started with a 60 kilogram cylinder of titanium and milled a very detailed crown out of it. 300 hours of CNC machining time on a very good 5-axis mill. Most of the metal ends up as scrap.
The software for this is called HyperMill. If you have to ask how much it costs, you can't afford it.
[1] https://www.youtube.com/watch?v=Bqv5SjC4s6w
Great article, though I'm surprised they didn't mention how the CIA clandestinely purchased much of the titanium for the SR-71 Blackboard (and it's predecessor) from Russia through front companies.
https://nationalinterest.org/blog/buzz/crazy-story-how-russi...
https://nationalinterest.org/blog/buzz/crazy-story-how-russi...
Heads up… except for mine almost none of the comments here mention Grade 5 (6AL4V).
This thread is a ton of people talking about things they think they understand but haven’t actually directly worked with. Just making things up or repeating things they heard once.
Anyone who actually uses it will know Grade 2, 5, 12, 23 etc.
I don’t mind particularly, there are some clearly educated people talking about chemistry, but it is important to note how many people here are talking out their asses.
The top current comment is about being unable to dent 4mm Ti plate with hammers - complete BS.
This thread is a ton of people talking about things they think they understand but haven’t actually directly worked with. Just making things up or repeating things they heard once.
Anyone who actually uses it will know Grade 2, 5, 12, 23 etc.
I don’t mind particularly, there are some clearly educated people talking about chemistry, but it is important to note how many people here are talking out their asses.
The top current comment is about being unable to dent 4mm Ti plate with hammers - complete BS.
> The top current comment is about being unable to dent 4mm Ti plate with hammers - complete BS.
It is about children with hammers.
It is about children with hammers.
Maybe you can educate us then..
I collect nice pocket knives. Many nice pocket knives are made from titanium and other fancy materials like carbon fiber. I love titanium above all other metals for its unique properties in being anodized and finished in a large variety of beautiful ways. If you are ever interested in seeing some truly unique and beautiful titanium finishes check out "Knife Modders" on instagram. Combinations of coatings/anodizing/laser etching can produce some truly beautiful pieces.
> it formed the literal backbone of the most advanced aerospace technology on the planet.
I'm going to be pedantic here, but I feel like it needs to be said: no, it was not the "literal" backbone aerospace technology. It was the "figurative" backbone. There, I said it.
I'm going to be pedantic here, but I feel like it needs to be said: no, it was not the "literal" backbone aerospace technology. It was the "figurative" backbone. There, I said it.
It does not need to be said.
The use of literally as an intensifier goes back centuries, and is well-accepted. Move on.
Why choose this hill to die on when there are far more interesting things to discuss?
The use of literally as an intensifier goes back centuries, and is well-accepted. Move on.
Why choose this hill to die on when there are far more interesting things to discuss?
Since the A-12 was 93% titanium, it's virtually certain that its skeletal frame was made of the metal. The word "literal" applies.
> After the war, the Bureau’s work on titanium accelerated. By 1947 it had successfully scaled up Kroll’s process
The article so far can be summarized as "people played around with titanium, but had no idea what to use it for" so why is the bureau suddenly trying to scale up production, or even mass producing it in the first place? It wasn't until 1948 that they identified engineering applications.
The article so far can be summarized as "people played around with titanium, but had no idea what to use it for" so why is the bureau suddenly trying to scale up production, or even mass producing it in the first place? It wasn't until 1948 that they identified engineering applications.
Great discussion here. I can pretty much see why people would make a career of metals engineering.
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This is a really interesting story!
This is the 5th time this story has been posted here. None of the other times received any comments and only a few points.
It's the first time I've seen it, and I'm glad I did because it's fascinating!
Also, this time seems to be going a bit differently... Perhaps timing is everything (see: bored people with their Thanksgiving families today...)
Also, this time seems to be going a bit differently... Perhaps timing is everything (see: bored people with their Thanksgiving families today...)
It started with the titanium iPhone didn’t it? Maybe more people have begun to understand the benefits practically
The timing of the submission is far more important than the nature of the article.
Time of day, time of week, other prominent distractions, etc have an increasingly outsized influence.
Time of day, time of week, other prominent distractions, etc have an increasingly outsized influence.
Come back, zinc! Come back!